German patent publication 299 08 541 discloses a connecting arrangement for coolant lines, especially, for motor vehicle climate control systems operated with CO2. In this connecting arrangement, the line endpieces of two coolant lines are each provided with a coupling piece. Both coupling pieces each include a radially running sealing surface on the end facing toward the other coupling piece. A metallic flat ring is seated between the sealing surfaces and has a peripheral recessed portion. The metallic flat ring, which is provided with a peripherally extending recessed portion, is pressed together by the threaded fastener of the two coupling pieces and ensures the necessary axial sealing of the connecting arrangement. The threaded connection of the two coupling pieces takes place in that a coupling piece is provided with an external thread on which a nut threadably engages and this nut is connected to the second coupling piece. Or, the coupling pieces are connected to each other by means of screws. The screws are arranged in a circle about and parallel to the axis of the line endpieces connected within the coupling pieces.
A connecting arrangement of this kind has the disadvantage that the assembly or disassembly thereof is very complex when only a limited space is available.